SAN FRANCISCO -- Wading into uncharted waters, a federal appeals court on Wednesday tussled with whether the same legal barriers against excluding women and minorities from juries apply to gays and lesbians.

During an hour of arguments, a three-judge 9th U.S. Circuit Court of Appeals panel appeared likely to determine that gays and lesbians are in fact entitled to those same constitutional protections, if they decide to address the closely-watched issue at this point.

The issue has surfaced in an antitrust showdown between pharmaceutical giants Abbott Laboratories and SmithKline Beecham, which are both seeking a new trial in an appeal of a mixed verdict handed down by a San Francisco federal jury two years ago.

At the outset of the trial, Abbott bumped a potential gay juror during jury selection, prompting SmithKline's lawyers to argue that Abbott deliberately excluded a gay man from a trial that centered on allegations the company dramatically hiked the price of a crucial HIV treatment drug. Abbott's pricing move outraged the gay community at the time.

As a result, the case has been transformed into a legal test of whether a landmark 1986 U.S. Supreme Court decision barring the exclusion of jurors based on race extends to gays and lesbians.

Lisa Blatt, SmithKline's lawyer, told the 9th Circuit that Abbott's position on the issue is "offensive."

"The equal protection clause bars using peremptory challenges to disqualify gays and lesbians from jury service," Blatt said. "Sexual orientation, like race and gender, can never be a valid consideration for striking a juror."

Daniel Levin, Abbott's attorney, urged the appeals court to avoid the gay juror issue altogether, saying the judges can simply side with SmithKline's antitrust arguments and steer clear of a broader constitutional ruling.

But the judges, citing the Supreme Court's language about anti-gay discrimination in the recent ruling striking down the federal government's ban on same-sex marriage benefits, pressed Levin hard on Abbott's argument that the Supreme Court's Batson decision, which prohibited the use of race in jury selection, does not apply to gays and lesbians.

"Isn't Batson about trying to avoid discrimination on the basis of a category?" Judge Mary Schroeder asked.

In the San Francisco trial, Abbott dismissed a potential juror during jury selection after he discussed his male partner's employment history. Abbott denied removing the juror because he was gay, but SmithKline, citing the case's importance to the gay community, argues the inference of bias warrants a new trial.

Howard Mintz covers legal affairs. Contact him at 408-286-0236 or follow him at Twitter.com/hmintz